The Bay of Pigs (Spanish: Bahía de los Cochinos) is an inlet of the Gulf of Cazones, located on the southern coast of Cuba. By 1910 it was included in Santa Clara Province, and then to Las Villas Province by 1961, but in 1976, it was reassigned to Matanzas Province, when the original six provinces of Cuba were re-organized into 14 new Provinces of Cuba.

The bay is historically important for the failed Bay of Pigs Invasion of 1961. The area is a site known for its diving, with an abundance of marine fauna, e.g. 30 species of sponges belonging to 19 families and 21 genera, to be found in the bay.

In Cuban Spanish, cochinos may also mean the queen triggerfish (Balistes vetula), which inhabit coral reefs in Bahía de Cochinos, in addition to the literal meaning, pigs (Sus scrofa).

This bay is approximately 30 kilometres (19 mi) south of Jagüey Grande, 70 kilometres (43 mi) west of the city of Cienfuegos, and 150 kilometres (93 mi) southeast from the capital city Havana. On the western side of the bay, coral reefs border the main Zapata Swamp, part of the Zapata Peninsula. On the eastern side, beaches border margins of firm ground with mangroves and extensive areas of swampland to the north and east. At the north end of the bay, the village of Buena Ventura is adjacent to Playa Larga (Long Beach). 35 kilometres (22 mi) southeast of that, Playa Girón (Giron Beach) at the village of Girón, named after the notorious French pirate Gilberto Giron (c. 1604).

Playa Girón and Playa Larga were the landing sites for seaborne forces of armed Cuban exiles and the land strip for some American planes (but not many as America did not want Cuba to realize that it was American sponsored) in the Bay of Pigs Invasion, an American CIA-sponsored attempt to overthrow the new government of Cuban Prime Minister Fidel Castro in April 1961.

According to Fidel Castro's former bodyguard, the late Juan Reinaldo Sánchez, Castro lived in great luxury and had a private island called Cayo Piedra in the Bay of Pigs, replete with "mansions, guest houses, a heliport, dolphinarium, turtle lagoon, his luxury yacht Aquarama – a gift from Leonid Brezhnev – and deep-sea fishing speedboat".

The Bay of Pigs is a relatively quiet site for diving. Dive centers exist in Playa Larga, Playa Girón and Caleta Buena. Twelve dive sites in the bay display excellent visibility of 20 to 40 metres (66 to 131 ft), an average water temperature of 22 °C (72 °F) in December and 29 °C (84 °F) in July. Walls of coral, caverns, and a variety of fish (including the barracuda, lionfish, and groupers, among others), coral, and sponges can be found in the Bay of Pigs.

The Caves of the Fishes (Spanish: Cueva de los Peces), with 72 metres (236 ft) depth the deepest cenote of Cuba, is located at 18 kilometres (11 mi) south of Playa Larga.

Surrounding the Bay of Pigs, the endemic wormlizards Amphisbaena barbouri and A. cubana have been noted. The following marine species have been registered along the eastern coast of the Bay of Pigs:

Group	Common name	Scientific name	Image	Notes
Fish	blue chromis	Chromis cyanea
	blue tang	Acanthurus coeruleus
	bluehead wrasse	Thalassoma bifasciatum
	striped parrotfish	Scarus iseri
	beau gregory	Stegastes leucostictus
	bicolor damselfish	Stegastes partitus
	boga	Inermia vittata
	Colon goby	Coryphopterus dicrus
	creole wrasse	Clepticus parrae
	longfin damselfish	Stegastes diencaeus
	masked goby	Coryphopterus personatus
	threespot damselfish	Stegastes planifrons
	yellowhead wrasse	Halichoeres garnoti
	French grunt	Haemulon flavolineatum
	ocean surgeon	Acanthurus bahianus
	sergeant major	Abudefduf saxatilis
	slippery dick	Halichoeres bivittatus
	yellowtail snapper	Ocyurus chrysurus
	bar jack	Caranx ruber
	barred hamlet	Hypoplectrus puella
	brown chromis	Chromis multilineata
	foureye butterflyfish	Chaetodon capistratus
	graysby	Epinephelus cruentatus
	longjaw squirrelfish	Holocentrus marianus
	redband parrotfish	Sparisoma aurofrenatum
	royal gramma	Gramma loreto
	stoplight parrotfish	Sparisoma viride
	tomtate grunt	Haemulon aurolineatum
	white grunt	Haemulon plumierii
	porgies	Calamus sp.
	banded butterflyfish	Chaetodon striatus
	buffalo trunkfish	Lactophrys trigonus
	flat needlefish	Ablennes hians
	glasseye	Heteropriacanthus cruentatus
	longspine squirrelfish	Holocentrus rufus
	plate fish	Bothus lunatus
	red lionfish (invasive)	Pterois volitans
	spotfin butterflyfish	Chaetodon ocellatus
	trumpetfish	Aulostomus maculatus
Sponges	azure vase sponge	Callyspongia plicifera
	yellow tube sponge	Aplysina fistularis
	green finger sponge	Iotrochota birotulata
	orange icing sponge	Mycale laevis
	pink vase sponge	Niphates digitalis
	row pore rope sponge	Aplysina cauliformis
	touch-me-not sponge	Neofibularia nolitangere
	demosponges	Cliona sp.
		Cliona aprica
		Cliona delitrix
		Cliona varians
		Aiolochroia crassa
		Ectyoplasia ferox
		Ircinia felix
		Mycale laxissima
		Plakortis angulospiculatus
		Scopalina ruetzleri
		Smenospongia aurea
		Spirastrella coccinea
Corals	boulder brain coral	Colpophyllia natans
	Caribbean sea whip	Plexaura homomalla
	elkhorn coral	Acropora palmata
	great star coral	Montastraea cavernosa
	maze coral	Meandrina meandrites
	purple sea fan	Gorgonia ventalina
	sea ginger	Millepora alcicornis
Crustaceans	Caribbean spiny lobster	Panulirus argus
Echinoderms	donkey dung sea cucumber	Holothuria mexicana
Mollusks	queen conch	Lobatus gigas

• Geography of Cuba

• Wyden, Peter (1979). Bay of Pigs – The Untold Story. New York: Simon and Schuster. ISBN 0-671-24006-4, 0224017543, 978-0-671-24006-6.